I'm not really sure that if you always train with gloves on a bag and then take those gloves off, you can hit as hard. A boxer could answer this question better than me. When you wear gloves the material on the inside of your hand prevents you from forming as tight a fist as the traditional bare seiken fist. This may or may not impair your ability to strike with the first two knuckles with approx. 30% of the force on the first knuckle and approx. 70% on the second (most prominent knuckle). With some people, the knowledge that they are no longer wearing gloves and may therefore injure their hands may act as an impediment to full power strikes. My view is if you are training to fight with gloves (eg a boxer or kickboxer) then train with gloves, if you are training to defend yourself (without gloves) then train without gloves, unless your occupation requires extremely good fine motor skills, such as a surgeon. Gloves don't seem to work well on a makiwarra, and the makiwarra is great for developing powerful straight line punches.